The latter half of the 19th century was a critical period in the development of Western, or what is now complimentarily called modern, medicine. The famed chemist Louis Pasteur and the physician Robert Koch established on a firm intellectual foundation the notion that the cause of infectious diseases often lay in organisms that existed outside the body.

This new philosophy paved the way for containing such scourges as smallpox and leprosy, curtailed the viciousness of tuberculosis and cholera, and germinated the subsequent, exponential rise of the antibiotic industry. Germ theory, as this approach is called, also broke ranks with so-called traditional systems of medicine, such as Ayurveda or the Chinese systems, which saw disease as the result of an imbalance between an individual and his environment.

However, an increasing number of cases of antibiotic-resistant tuberculosis and modern medicine’s failure to explain epidemics such as obesity and cardiovascular disease have seen a rise in schools of alternative medicine. The latter seek to reinterpret traditional medicine—often in a tone of triumphalism—in terms of modern medicine and try to close that breach, one zany theory at a time.

All About Bacteria: HarperCollins India, 235 pages, Rs299.

Health writer Ravi Mantha’s concise book, All About Bacteria, straddles the genre of popular science and alternative-medicine advocacy and claims that it is time to revisit our preponderantly negative perception about, of all things, bacteria. He focuses on the billions of bacteria that populate our gut and maintain a beneficial relationship with us, and there are many intriguing—positively astounding—nuggets on bacterium such as Mycobacterium vaccae. This close cousin of the tuberculosis bacterium is found in cow dung, and is one of the reasons why gardeners and villagers rarely suffer from depression. That’s because M. vaccae stimulates the release of serotonin, among the trio of “happy” chemicals, in humans.

Mantha passionately argues that bathing and swabbing floors with disinfectant are overrated and may counter-beneficially promote the development of more virulent, pathogenic strains of bacteria. He lambasts the pharmaceutical and consumer-health industries for whipping up a fear psychosis with a relentless stream of images that show us under constant attack by invisible, dangerous microbes, and in his enthusiasm frequently ends up overstating the little that science truly understands about the bacterial world.

For instance, he argues that the pharma industry’s advocacy of a class of drugs called statins, to counter high cholesterol, may be counterproductive eventually, as these drugs are frequently associated with impaired liver function and “neurodegenerative illnesses”.

All one needs to do, then, to counter heart disease is to brush and floss regularly. That’s because heart disease is due to elevated levels of cortisol, a chemical that’s frequently released to counter stress. The biggest source of stress, according to Mantha, is “chronic inflammation of the teeth, or dental disease”. Therefore, clean your teeth and beat heart disease.

While it isn’t the case that science may throw up counter-intuitive explanations for diseases, Mantha throws in several of these iffy syllogisms without attribution or any reference to proven studies. Because Mantha is neither a researcher nor doctor, there is additional onus on him to source statements of fact from peer-reviewed literature.

Then there are egregious errors of perfunctory research where he says that “in many parts of Asia, people eat a largely carb-based diet with no noticeable obesity issues”. While a far fewer proportion of adults in India are obese compared with the US, obesity levels in India alone rose from 23.4% of the urban population to 40% within 11 years, according to a study conducted in 2006 in India and published in the Journal of Obesity.

It is because the reader is now unsure which of his assertions about bacteria are verifiable and which of them in the realm of speculation that Mantha’s breezily-written, well-structured book degenerates into pop advocacy rather than what could have been a classy science book about the mysterious and intriguing world of bacteria, which collectively outweigh all the plants and animals put together.